On a special holiday weekend like Thanksgiving, the testing break is especially disruptive, writes Erin Kissane, a founder of the COVID Tracking Project at The Atlantic. Many test sites, labs, and health departments took off Thanksgiving and the long weekend. As they work through the backlog of tests in the next few days, we’ll likely see a misleading decline in cases early in the week followed by a huge surge.

But that’s not all: We’re also likely to see a historic increase in testing from all these people returning from their Thanksgiving vacation. On Sunday, the White House coronavirus-task-force coordinator, Deborah Birx, told CBS that everybody who traveled should “assume that you were exposed and you became infected.” That would mean tens of millions of people trying to get tested in the next week or so, leading to a backlog on top of the backlog.

In sum, the next few weeks are going to be a statistical blur at the very moment when families are looking for clarity regarding the winter holidays. As COVID-19 hospitalizations reach an all-time high, we are facing a normal weekend testing delay, exacerbated by a major holiday, complicated by the already rising COVID-19 caseload, and further burdened by the imminent wave of tests that will be demanded by people coming back from their Thanksgiving trip. For that reason, state and local governments, businesses, and families might have to fly blind for a while in the fog of pandemic.